Microbial cells, such as bacteria, fungi, archaea, or viruses are often used as carriers in genomic research to replicate or express specific genes or proteins. Isolates of particular microbial species or variants are often isolated from mixed microbial populations. When grown in petri dishes, microbial cells usually form colonies. The microbial colonies can be hand-picked using a picker, such as a toothpick, and placed in individual wells of a microwell plate for subsequent incubation. Such hand-picking can be time consuming and tedious.
Automated systems for colony picking became available in recent years. In these systems, microbial colonies can be identified by computer vision technology, and a picker mounted on a robotic arm can be used to transfer material from selected colonies to destination microwell plates (such as 96-well or 384-well plates). However, as the size of the colonies may be quite large (in a range of millimeters, for example) and the colonies of interest may appear in unpredictable positions, these automated systems require analysis of the image of the culture media for detection of the right colony to pick from, which could involve complicated optical component as well as image analysis software. Further, the precision of the picking can be low.